Symptoms
Workflow stops with '7008 The following error occurred while executing policy for CustomEventInstanceID: 9 : Unauthorized Assembly' in consolein console
Diagnoses
This error was a tough one to troubleshoot.
Resolution
There was a differentiation in the client's Hostserver.exe.config file and was updates with the new values.
Compared the client's hostserver.exe.config file with my own denallix VM's file and found the difference.